CONTENTS. 



Page. 



Introduction 7 



Classification of dry-farming regions 8 



Importance of knowing the normal rainfall 8 



Many rainfall stations necessary on account of local variations in rainfall 9 



The distribution of the annual rainfall in dry -farming regions 10 



Comparison of the monthly distribution of rainfall in the Great Plains, Inter- 

 mountain, and Pacific coast regions : 12 



The relation of monthly distribution of rainfall to farm practice 13 



The relation of the character of rainfall to its usefulness 14 



Run-off during torrential rains 15 



Hail 16 



Evaporation in dry-farming sections 16 



Evaporation as influencing agriculture in the Great Plains 20 



Relation of yield to rainfall 23 



Relation of yield to rainfall in the Great Basin 23 



Minimum rainfall necessary for wheat production in the Columbia Basin. . 24 



Relation of yield to rainfall in the Great Plains 25 



Yield in relation to rainfall in southern Texas 30 



The three years' record at San Antonio 30 



Summer tillage at San Antonio 31 



Normal precipitation of the western United States 32 



Index 67 



188 5 



